Earlier Highlights (5)
In June 2004, Jun Makino and I released the first version of our Art of Computational Science (ACS) software, ACS 1.0. This package contains the text of four new volumes in the ACS series, bringing the total up to more than 700 pages. In addition, the package contains the computer codes introduced in the text.
In May 2004, funding was announced for a new GRAPE project. Unlike previous special-purpose computers in the GRAPE series, the new GRAPE will be a general-purpose computer, containing several hundred processors per chip. The peak speed for N-body simulations is expected to be 2 Petaflops, to be realized by 2008. See the GRAPE web site for more background.
In April 2004, Douglas Heggie and I wrote a self-scheduling N-body code, as a toy model to demonstrate how an N-body code can run without any central scheduler. A call to print out the N-body system at a future time triggers ripples of activity, each particle asking their neighbors for their new positions, in order to propagate themselves into the future.
<- Also in April, Simon Portegies Zwartet al. published a paper in Nature in which we report the results of a number of star-by-star simulations of young star clusters in M82, each containing more than 100,000 stars. We use these simulations to suggest the formation in cluster MGG-11 of an intermediate-mass black hole, corresponding to a powerful X-ray source, through a run-away process of collisions of massive stars there during the last ten millions years.
In March 2004, we organized MODEST-4a, an N-Body School in which students could get hands-on experience in using not only simulation packages, but also in adapting the various source codes to their own projects. The School was held in Strasbourg, France, as the first MODEST satellite meeting.
In February 2004, I participated in 2004 Planetary Defense Conference: Protecting Earth from Asteroids where our B612 Foundation gave various presentations, starting off with the Founders III workshop.
<- Also in February, Yoko Funato, three other Japanese colleagues and I published a paper in Nature in which we described a new way to form binaries in the Kuiper belt, a region just beyond Neptune where many small bodies have been found since the first discovery in 1992 (we almost got there first).
In January 2004, we organized MODEST-4, in Lausanne, Switzerland. This was the fourth in a series of workshops to discuss MOdeling DEnse STellar systems, and the second such meeting in Europe.
In November 2003, Rusty Schweickart, Ed Lu, Clark Chapman and I published The Asteroid Tugboat in Scientific American, 289, Number 5, pp. 54-61. We discussed how to build and test a spacecraft that could push an asteroid into a new orbit as a way to protect the Earth from catastrophic impacts.
Also in November, John Conway directed me to Neil Sloane, who analyzed and then added my coathanger sequence, a byproduct of my work in counting hierarchical equilibrium configurations of multiple star systems, to his On-Line Encyclopedia of Integer Sequences, where you can find my original coathanger sequence, as well as a triangle decomposition of the sequence. As for the astrophysical interpretation, see the comments for multiple star systems and bound multiple star systems.